﻿#include "snake.h"

void SetPos(int x, int y)
{
	//获得标准输出的设备的句柄
	HANDLE houtput = NULL;
	houtput = GetStdHandle(STD_OUTPUT_HANDLE);

	//定位光标的位置
	COORD pos = { x,y };
	SetConsoleCursorPosition(houtput, pos);
}

//欢迎界面
void WelcomeToGame()
{
	SetPos(40, 14);
	wprintf(L"欢迎来到贪吃蛇小游戏\n");

	SetPos(42, 20);
	system("pause");
	system("cls");//清理屏幕

	SetPos(28, 14);
	wprintf(L"用↑.↓.←.→来控制蛇的移动，按F3加速，F4减速\n");

	SetPos(28, 15);
	wprintf(L"加速能够得到更高的分数\n");

	SetPos(42, 20);
	system("pause");
	system("cls");//清理屏幕
}

//绘制地图
void CreatMap()
{
	//上
	for (int i = 0; i < 29; i++)
	{
		wprintf(L"%c", L'□');
	}

	//下
	SetPos(0, 26);
	for (int i = 0; i < 29; i++)
	{
		wprintf(L"%c", L'□');
	}
	 
	//左
	for (int i = 1; i <= 25; i++)
	{
		SetPos(0, i);
		wprintf(L"%c", L'□');
	}
	
	//右
	for (int i = 1; i <= 25; i++)
	{
		SetPos(56, i);
		wprintf(L"%c", L'□');
	}

}

// 4.初始化蛇
void InitSnake(pSnake ps)
{
	int i = 0;
	pSnakeNode cur = NULL;

	for (int i = 0; i < 5; i++)
	{
		cur = (pSnakeNode)malloc(sizeof(SnakeNode));
		if (cur == NULL)
		{
			perror("InitSnake()::malloc()");
			return;
		}
		cur->next = NULL;
		cur->x = POS_X + 2 * i;
		cur->y = POS_Y;

		//头插法插入链表
		if (ps->_pSnake == NULL)
		{
			ps->_pSnake = cur;
		}
		else
		{
			cur->next = ps->_pSnake;
			ps->_pSnake = cur;
		}
	}
	cur = ps->_pSnake;
	while (cur)
	{
		SetPos(cur->x, cur->y);
		wprintf(L"%lc", BODY);
		cur = cur->next;
	}

	//设置贪吃蛇的属性
	ps->_dir = RIGHT;//默认向右
	ps->_score = 0;
	ps->_food_weight = 10;//每个食物二点分数
	ps->_sleep_time = 200;//单位是毫秒
	ps->_status = OK;//正常状态

}


// 5.创建食物
void CreatFood(pSnake ps)
{
	int x = 0;
	int y = 0;
again:
	do
	{
		x = rand() % 53 + 2;
		y = rand() % 25 + 1;
	} while (x % 2 != 0);

	//x和y坐标不能和蛇身的坐标冲突
	pSnakeNode cur = ps->_pSnake;
	while (cur)
	{
		if (x == cur->x && y == cur->y)
		{
			goto again;
		}
		cur = cur->next;
	}

	//创建食物节点
	pSnakeNode pFood = (pSnakeNode)malloc(sizeof(SnakeNode));
	if (pFood == NULL)
	{
		perror("CreateFood()::malloc()");
		return;
	}
	pFood->x = x;
	pFood->y = y;
	pFood->next = NULL;

	SetPos(x, y);
	wprintf(L"%lc", FOOD);

	ps->_pfood = pFood;
}


//初始化游戏
void GameStart(pSnake ps)
{
	// 0.光标隐藏
	system("mode con cols=100 lines=30");
	system("title 贪吃蛇");
	HANDLE houtput = GetStdHandle(STD_OUTPUT_HANDLE);
	//隐藏光标操作
	CONSOLE_CURSOR_INFO CursorInfo;
	GetConsoleCursorInfo(houtput, &CursorInfo);//获取控制台光标信息
	CursorInfo.bVisible = false;//隐藏控制台光标
	SetConsoleCursorInfo(houtput, &CursorInfo);//设置控制台光标状态

	// 1.打印环境界面
	// 2.功能介绍
	WelcomeToGame();

	// 3.绘制地图
	CreatMap();

	// 4.初始化蛇
	InitSnake(ps);
	
	// 5.创建食物
	CreatFood(ps);

	// 6.设置游戏的相关信息


}

//打印帮助信息
void PrintfHelpInfo()
{
	SetPos(64, 13);
	wprintf(L"%ls", L"游戏规则：");

	SetPos(64, 14);
	wprintf(L"%ls", L"不能穿墙，不能咬到自己");
	SetPos(64, 15);
	wprintf(L"%ls", L"用↑.↓.←.→来控制蛇的移动");
	SetPos(64, 16);
	wprintf(L"%ls", L"按F3加速，F4减速");

	SetPos(64, 17);
	wprintf(L"%ls", L"按ESC退出游戏，按空格暂停游戏");

	SetPos(64, 19);
	wprintf(L"%ls", L"JoknKi制作");
}

//暂停 -> 睡眠
void pause()
{
	while (1)
	{
		if (KEY_PRESS(VK_SPACE))
		{
			break;
		}
	}
}

//检测下一个坐标是否是食物
int NextIsFood(pSnakeNode pn, pSnake ps)
{
	return(ps->_pfood->x == pn->x && ps->_pfood->y == pn->y);
}

//吃掉食物
void EatFood(pSnakeNode pn, pSnake ps)
{
	//头插法
	ps->_pfood->next = ps->_pSnake;
	ps->_pSnake = ps->_pfood;

	//释放下一个位置的节点
	free(pn);
	pn = NULL;

	pSnakeNode cur = ps->_pSnake;

	//打印
	//while (cur)
	//{
	//	SetPos(cur->x, cur->y);
	//	wprintf(L"%lc", BODY);
	//	cur = cur->next;
	//}
	SetPos(cur->x, cur->y);
	wprintf(L"%lc", BODY);
	ps->_score += ps->_food_weight;

	//重新创建食物
	CreatFood(ps);
}

//下一个位置不是食物
void NoFood(pSnakeNode pn, pSnake ps)
{
	//头插法
	pn->next = ps->_pSnake;
	ps->_pSnake = pn;

	pSnakeNode cur = ps->_pSnake;
	while (cur->next->next != NULL)
	{
		SetPos(cur->x, cur->y);
		wprintf(L"%lc", BODY);
		cur = cur->next;
	}

	SetPos(cur->next->x, cur->next->y);
	printf("  ");
	
	free(cur->next);
	cur->next = NULL;

	KillBySelf(ps);

	KillByWall(ps);

}

//撞墙
void KillByWall(pSnake ps)
{
	if (ps->_pSnake->x == 0 || ps->_pSnake->x == 56 || ps->_pSnake->y == 0 || ps->_pSnake->y == 26)
	{
		ps->_status = KILL_BY_WALL;
		return 1;
	}
	return 0;
}

//撞到自己
void KillBySelf(pSnake ps)
{
	pSnakeNode cur = ps->_pSnake->next;
	while (cur)
	{
		if (ps->_pSnake->x == cur->x && ps->_pSnake->y == cur->y)
		{
			return 1;
		}
		cur = cur->next;
	}
	return 0;
}

//蛇走一步
void SnakeMove(pSnake ps)
{
	//创建一个节点，表示蛇即将到的下一个节点
	pSnakeNode pNextNode = (pSnakeNode)malloc(sizeof(SnakeNode));
	if (pNextNode == NULL)
	{
		perror("SnakeMove()::malloc()");
		return;
	}

	switch (ps->_dir)
	{
	case UP:
		pNextNode->x = ps->_pSnake->x;
		pNextNode->y = ps->_pSnake->y - 1;
		break;
	case DOWN:
		pNextNode->x = ps->_pSnake->x;
		pNextNode->y = ps->_pSnake->y + 1;
		break;
	case LEFT:
		pNextNode->x = ps->_pSnake->x - 2;
		pNextNode->y = ps->_pSnake->y;
		break;
	case RIGHT:
		pNextNode->x = ps->_pSnake->x + 2;
		pNextNode->y = ps->_pSnake->y;
		break;
	}

	//检测下一个坐标是否是食物
	if (NextIsFood(pNextNode,ps))
	{
		EatFood(pNextNode, ps);
	}
	else
	{
		NoFood(pNextNode, ps);
	}



}

//游戏运行逻辑
void GameRun(pSnake ps)
{
	//打印帮助信息
	PrintfHelpInfo();

	do
	{
		//打印总分数和食物的分值
		SetPos(64, 10);
		printf("总分数:%2d", ps->_score);
		SetPos(64, 11);
		printf("当前食物的分数是：%2d", ps->_food_weight);

		//调整方向
		if (KEY_PRESS(VK_UP) && ps->_dir != DOWN)//向下
		{
			ps->_dir = UP;
		}
		else if (KEY_PRESS(VK_DOWN) && ps->_dir != UP)//向上
		{
			ps->_dir = DOWN;
		}

		else if (KEY_PRESS(VK_LEFT) && ps->_dir != RIGHT)////向左
		{
			ps->_dir = LEFT;
		}
		else if (KEY_PRESS(VK_RIGHT) && ps->_dir != LEFT)//向右
		{
			ps->_dir = RIGHT;
		}
		else if (KEY_PRESS(VK_SPACE))//暂停
		{
			pause();
		}
		else if (KEY_PRESS(VK_ESCAPE))//退出
		{
			//正常退出游戏
			ps->_status = END_NORMAL;
		}
		else if (KEY_PRESS(VK_F3))//加速
		{
			if (ps->_sleep_time > 80)
			{
				ps->_sleep_time -= 30;
				ps->_food_weight += 2;

			}
		}
		else if (KEY_PRESS(VK_F4))//减速
		{
			if (ps->_food_weight > 2)
			{
				ps->_sleep_time += 30;
				ps->_food_weight -= 2;
			}
		}

		//贪吃蛇走一步
		SnakeMove(ps);
		Sleep(ps->_sleep_time);


	} while (ps->_status == OK);
}


//游戏结束
void GameEnd(pSnake ps)
{
	pSnakeNode cur = ps->_pSnake;
	SetPos(24, 12);
	switch (ps->_status)
	{
	case END_NORMAL:
		printf("您主动退出游戏\n");
		break;
	case KILL_BY_SELF:
		printf("您撞上⾃⼰了 ,游戏结束!\n");
		break;
	case KILL_BY_WALL:
		printf("您撞墙了,游戏结束!\n");
		break;
	}
	//释放蛇⾝的节点
	while (cur)
	{
		pSnakeNode del = cur;
		cur = cur->next;
		free(del);
	}
}
